Dark Matter Found? Orbital Experiment Detects Hints
Did you own a toy race-car track as a child? Ever crash your model trains into one another just to see what happened? If you did, then congratulations, you already know some of the basic principles behind the Large Hadron Collider (LHC). Built by the European Organization for Nuclear Research (CERN), the 27-kilometer tunnel buried in the Swiss countryside exists to smash particle beams into each other at velocities approaching the speed of light. The idea is to use the resulting data to better understand the structure and origins of the universe. We're talking heavy questions and even heavier answers. Perhaps it's understandable that some critics, conspiracy theorists, crackpots and (alleged) time travelers might fear something more substantial than the Higgs boson particle. In this article, we'll run through some of the more popular misconceptions about the LHC and how little you have to fear about it causing the end of the world as we know it.
5. CERN Is Making an Antimatter Bomb
The Dan Brown detective novel (and movie adaptation) "Angels and Demons" centers on a plot to steal an antimatter bomb from CERN and blow up the Vatican with it. While the blockbuster delivered its share of action and intrigue, it fell short on facts. Two of the film's biggest mistakes revolved around antimatter's potential use as both an energy source and a weapon. Yes, when an antimatter particle comes in contact with normal matter, the two particles destroy each other and release energy. But CERN is quick to point out that the energy payoff simply isn't there. In fact, the transaction is so inefficient that scientists only get a tenth of a billionth of their invested energy back when an antimatter particle meets its matter counterpart. As for developing an antimatter bomb, the same principles apply. CERN points out that, at current production rates, it would take billions of years for the organization to produce enough antimatter to generate an explosion equal to an atomic blast.
4. Fun-sized Black Holes
Some concepts don't become tamer when you tack a "micro-" or a "mini-" prefix in front of them. For example, a mini-stroke is still an excellent reason to visit the hospital, and you'd certainly be ill advised to question the power of a minigun. So when CERN scientists mention that they might create microscopic black holes in the midst of their particle smashing, it's easy to understand some of the ensuing panic. Based on Einstein's theory of relativity, a few speculative theories lend a sheen of possibility to micro-black hole creation. The good news is that these theories also predict the micro-black holes would disintegrate immediately. If these black hole welterweights did hang around a little longer, it would take billions of years to consume the mass of a tiny grain of sand. That means no reducing the European countryside to a singularity and certainly no destroying the planet "Star Trek" style.
3. Attack of the Strangelets
Read enough space publications and your perception of the universe changes pretty fast. Once you get beyond the absurd vastness of the cosmos, you encounter such mind-rending notions as black holes, antimatter and dark matter. After you've swallowed the notion of a gigantic star collapsing into something smaller than a pinhead, it's easy to get bowled over by the idea of universe-destroying strangelets. Strange matter is presumed to be 10 million times denser than lead and was birthed during the Big Bang from the hearts of dense stars. The fear, which originated with the start-up of the Relativistic Heavy Ion Collider (RHIC) in 2000, is that the LHC will inadvertently produce strangelets -- tiny particles of strange matter -- and that these particles will swiftly convert surrounding normal matter into even more strange matter. It only takes a thousand-millionth of a second for the chain reaction to convert the entire planet. Strangelets, however, are purely speculative, and haven't surfaced in over eight years of RHIC operation. CERN says that the RHIC was far more likely to produce the theoretical matter than the LHC, so there's really no chance of it consuming the planet.
2. Time Travelers Hate It
In "Bill & Ted's Excellent Adventure," the titular slacker duo wields time travel with the logic of a 12-year-old. When Bill and Ted need a cell key to bust a few historical figures out of a modern California jail, they simply make a mental note for their future selves to travel back in time and plant the key where they can find it. While the 1989 buddy comedy is pretty much the antithesis of hard science fiction, its view of time-travel logic is shockingly similar to a 2009 theory regarding the LHC. Danish string theory pioneer Holger Bech Nielsen and Japanese physicist Masao Ninomiya, in a series of posted physics articles, laid out their theory that the Higgs boson particle is so abhorrent to nature that its future creation will send a ripple back through time to keep it from being made. Naturally, this theory summons images of T-800s, Jean-Claude Van Damme and Hermione Granger all galloping back through time to prevent future disasters, but not everyone is busy cracking jokes and reminiscing about time-travel movies. The two scientists aren't even talking about shadowy strangers from the future, but merely "something" looping back through the fourth dimension. Imagine a poorly designed bomb that, upon creation, destroys half the bomb factory. Now expand that example out from the confines of linear time.
1. Gateway to Hell
Black holes, antimatter explosions and even strangelets all originate from scientific fact and theory (albeit with a bit of imagination thrown in). Forget all that for the moment and consider the "Satan's Stargate" theory, proposed by Chris Constantine, better known on the Internet as YouTube user gorilla199. Constantine charges that the LHC exists "to disrupt a hole in the Van Allen belt that surrounds the Earth" and "to allow the return of the Annunaki from the planet Nibiru in order that they can come here, corrupt the rest of the Earth and do battle with God at Armageddon." There's also some stuff in there about freemasonry, cosmic rays and the Old Testament offspring of humans and fallen angels. According to BBC News, Constantine received a suspended sentence for DVD pirating after his defense attorney charged that Constantine suffered from a serious psychiatric condition. The Antichrist could not be reached for comment.
A $2 billion particle detector attached to the International Space Station has detected the potential signature of dark matter annihilation in the Cosmos, scientists have announced today.
The Alpha Magnetic Spectrometer (AMS) was attached to the space station in May 2011 by space shuttle Endeavour — the second-to last shuttle mission to the orbital outpost. Since then, the AMS has been detecting electrons and positrons (the electron’s anti-particle) originating from deep space and assessing their energies. By doing a tally of electrons and positrons, physicists hope the AMS will help to answer one of the most enduring mysteries in science: Does dark matter exist?
And today, it looks like the answer is a cautious, yet exciting, yes.
Results from the AMS have been highly anticipated, and in a special announcement to be made at 1:30 p.m. EDT (6:30 p.m. GMT) today (April 3) the first results from billions of particle detections will be detailed. The details of the research have also been revealed by a CERN announcement ahead of the study being published in the journal Physical Review Letters.
Around 400,000 positron detections have been confirmed in this first batch of data — positrons that are of energies consistent with the signature of dark matter annihilation.
Dark matter is thought to make up 80 percent of all matter in the Universe, the rest is “baryonic matter” — i.e. the stuff we’re made of. But the vast majority of matter is locked in an invisible component of matter. As the moniker suggests, dark matter is dark; it doesn’t interact with electromagnetic radiation. However, dark matter still carries mass that has a gravitational effect on space-time and through indirect means we can detect its gravitational presence.
Theory suggests that Weakly-Interacting Massive Particles (WIMPs) may be a part of non-baryonic matter, bulking up the mass of the Universe. WIMPs are their own anti-particles; when two WIMPs collide, they annihilate and produce positrons and electrons (and energy). But for physicists to confirm WIMP annihilation does occur, the positrons need to have a specific energy signature.
Positrons with energies of 0.5 GeV to 250 GeV have been recorded by the AMS — the largest collection of antimatter particles recorded in space. “The positron fraction increases from 10 GeV to 250 GeV, with the data showing the slope of the increase reducing by an order of magnitude over the range 20-250 GeV,” writes the CERN release. This is consistent with the theory that WIMPs are out there, annihilating. And, apparently, these positrons are originating from all directions, bolstering the theory that dark matter permeates the whole Universe.
Other space-based experiments have seen clues of this dark matter signature, such as the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instrument. But their measurements of the particle energy spectra have been too “coarse”; the AMS can produce a very refined spectrum of positron energies, allowing scientists an unprecedented high-resolution view of positron energies.
But this is by no means proof of WIMPs and a positive identification of dark matter annihilation. Pulsars — rapidly-spinning neutron stars — could also be generating this positron signal, so further work needs to be done.
“As the most precise measurement of the cosmic ray positron flux to date, these results show clearly the power and capabilities of the AMS detector,” said Nobel laureate Samuel Ting, of the Massachusetts Institute of Technology (MIT) who leads the international AMS team, in the CERN announcement. “Over the coming months, AMS will be able to tell us conclusively whether these positrons are a signal for dark matter, or whether they have some other origin.”
The AMS will remain attached to the space station for the rest of its operational life, so there are many more years of results to be taken and analyzed.
The orbiting particle detector isn’t only hunting for dark matter. Another quandary facing modern physics is why the Universe is composed mainly of matter (and not antimatter). Through the careful analysis of electron/positron ratios, it is hoped that some idea as to why the processes immediately after the Big Bang favored matter over antimatter will be gleaned.
While today’s AMS dark matter announcement is exciting, it is only the beginning of a long road of scientific discovery as to the origins of the Universe.
Image: The AMS attached to the exterior of the space station. Credit: NASA